I thought i replied to this last night but I guess it didnt go through
The panels suck. They are of the pull and pray variety. They are held on by push pin door clips. The problem with these is they break. I actually broke one taking the panel off and then stopped because I didnt have any in stock.
You may be ok because you do have two sets of seatbacks and to be honest, you can live without a clip or two. But If you break enough of them that the seatback doesnt go back on, you can get replacement clips from nissan or autozone or even online.
I keep some universal ones in stock and just trim them if they don't fit quite right. But unless you're pulling off doors and seatbacks constantly, just get ones that match what you have and you'll be fine.
You may want to get some trim tools too, may make the process easier.
something like this
http://www.amazon.com/Neiko-Auto-Body-P ... B000V664V2
you can use them to pry around the clips to get the seatback off.